This invention relates generally to internal combustion engines, and more particularly to a device for supplying supplemental air to the fuel-air mixture ingested by the engine from the carburetor in order to make the engine more fuel efficient.
In many gasoline engines, fuel is supplied to the intake manifold of the engine by way of a carburetor having a filtered air intake. During operation of the engine, air is drawn in through the carburetor over a layer of gasoline sitting in a bowl within the carburetor. The gasoline in the bowl is maintained at a certain level which is unrelated to engine displacement and power output. Even with optimum carburetion, some relatively large droplets or particles of gasoline or other fuel become mixed with the fuel vapor being drawn into the engine cylinders via the engine intake manifold. During the combustion process, these droplets do not burn completely. Therefore the fuel comprising those droplets does not contribute as much as it should to engine output power and it is expelled from the combustion chambers, appearing in the engine exhaust as unburned hydrocarbons or other atmospheric pollutants.
Various apparatus have been proposed heretofore to improve the fuel efficiency of internal combustion engines. However, these prior devices have tended to be rather complicated and to require active control by the vehicle operator.
For example, the device described in U.S. Pat. No. 4,055,159 has a filter funnel which takes in air and delivers it by way of a valve to the carburetor and the engine's PVC valve. Control means operatively associated with the valve and present inside the vehicle enable the vehicle operator to open and close the valve. U.S. Pat. No. 3,854,463 discloses a device for increasing engine efficiency which includes a funnel that conducts air from a vaporizing chamber which vaporizes fuel. Those fuel vapors are then conducted to the carburetor air intake. An electrically operated liquid level control maintains a supply of fuel in the vaporizing chamber. U.S. Pat. No. 4,279,236 discloses a fuel saving system which employs air scoops to conduct additional air to the carburetor air intake and to ventilate the engine crank case. Special aspirators are included in the system to separate gases with heavy particulates from gases containing lighter particulate matter. The heavier particulates are heated by heat from the exhaust manifold to form lighter particles which are then drawn back into the air flow by another aspirator and eventually routed to the intake filter of the carburetor. U.S. Pat. No. 4,235,209 discloses a device for pumping additional air by way of a multiple orifice unit The multiple orifice unit has a multiplicity of slot orifices to provide a sonic air flow condition at all engine speeds so that the air supply is maintained constant.
Aside from being relatively complex as noted above, these prior devices fail to mix the added air intimately enough with the fuel that powers the engine. As a result, engine operation is not as efficient as it might be so the engine is still deficient in terms of mileage per gallon of fuel consumed. Also, engines equipped with those devices still discharge relatively large amounts of pollutants into the atmosphere.